WHY SUCH A YUGE PROBLEM NOW?
In 2006, at the time it was passed, George W. Bush's White House touted the fence as "an important step toward immigration reform."[1] The White House Office of the Press Secretary stated that the Act "Authorizes the construction of hundreds of miles of additional fencing along our Southern border; Authorizes more vehicle barriers, checkpoints, and lighting to help prevent people from entering our country illegally; Authorizes the Department of Homeland Security to increase the use of advanced technology like cameras, satellites, and unmanned aerial vehicles to reinforce our infrastructure at the border."
https://en.wikipedia.org/wiki/Secure_Fence_Act_of_2006